Problem: Simplify the following expression: ${-4(9-5z)+8(6z+1)}$
Answer: Distribute the ${-4}$ into the first set of parentheses: $ {-4(}\gray{9-5z}{)} + 8(6z+1) $ $ {-36+20z} + 8(6z+1) $ Distribute the ${8}$ into the parentheses: $ -36+20z + {8(}\gray{6z+1}{)} $ $ -36+20z + {48z+8} $ Rewrite the expression to group the ${z}$ terms and numeric terms: $ {20z + 48z} {-36 + 8}$ Combine the ${z}$ terms: $ {68z} {-36 + 8}$ Combine the numeric terms: $ {68z} {-28}$ The simplified expression is $68z-28$